Priming apparatus for centrifugal pumps



March 17, 1936. A. c. DURDIN, JR

PRIMING APPARATUS FOR CENTRIFUGAL PUMPS Filed Marqh 18, 1935 INVENTORT Mayusfaa CflU fl/hJ/t BY 4L4 ATTORNEY.

Patented Mar. 17, 1936 UNITED I STATES PATENT OFFICE Augustus o. nurain, Jr., Niles Center,

signor to Chicago Pump Company, Chi

cage,

11]., a corporation of Illinois Application March 18,-1935, Serial No. 11,581 9 Claims. "(01.103-113) This invention relates to priming apparatus for centrifugal pumps and is in the nature of an improvement upon the priming apparatus shown and described in my pending application for patent filed February 11, 1935 under Serial No. 6,003.

One of the objects of the present invention is to simplify and otherwise improve upon the means for preventing water or other liquid from being drawn into the suction line and thence to the priming pump. Another object is to provide novel priming apparatus whereby one'priming pump may be used to serve several centrifugal pumps. As in the priming apparatus disclosed in my priorapplication, the priming apparatus of several centrifugal pumps may be connected by suction lines to a vacuum tank from which air is exhausted by a vacuum pump, either of the "dry vacuum or "wet vacuum type.

In priming apparatus of the present type. a

float is used tooperate the valve mechanism of the priming apparatus which controls the port between the float chamber and the suction line, and also controls the admission of air to the priming apparatus, and one of the objects of the present invention is to provide novel means for holding the float down until the level of the water in the float chamber reaches a certain level at which the upward pressure of the water will suddenly raise the float and close the inlet port to the suctionline without permitting any appreciable amount of air, under, atmospheric pressure, to enter the float chamber. Another object is to utilize the suction on one of the valves to yieldably hold the float up and the valve seated until the water in the float chamber recedes below a level that is necessary to buoy up the float whereby the valve mechanism may be shifted suddenly. Another object is to use a single valve for controlling the port to the suction line, in priming apparatus wherein means are provided for preventing the vacuum in the suction .line from being broken. Another object is to provide novel means to prevent the escape of water from the float chamber to the suction line in case the valve leaks. Another object is to eliminate the use of check valves in priming apparatus. Other objects and advantages will occur in the course of this specification and with said objects and advantages in view, this invention consists in the several novel features hereinafter fully set forth and claimed.

The invention is clearly illustrated in the drawing accompanying this specification in which:

Fig. 1 is a plan of priming mechanism for centrifugal pumps. embodying the preferred form of the present invention; Fig. 2 is a central vertical section of the priming apparatus, a fragment of the centrifugal pump and water connections, taken on the line 5 2-2 of Fig. 1; 4

Fig. 3 is a-horizontal section taken on the line HofFig.2;

Fig. 4- is a fragmental horizontal section through a slightly modified form of the inven- 10 tion, the line of section being indicated at 4-4 of Fig. 5, and v I Fig. 5 is a central vertical section taken on the lineS-S of Fig. 4. 1

Referring to said drawing and first to Figs. 1 15 to 3 inclusive, which are illustrative of themeferred embodiment of the invention, the reference character In designates the conventional suction pipe of a centrifugal pump installation, at the upper end of which suction pipe is an el- 20 bow ll connected by a T fitting I2 to the suctio side of a centrifugal pump, a fragment of wb ch is at l5. Usually a hand hole I3 is provided in the T fitting l2 which is closed by a cover l4 bolted to thefitting. 25 Extending upwards from the vertical branch of the T fitting is a float chamber casing 16 having a reduced neck H at its lower end, which is bolted to the T fitting and an enlarged hollow body l8 above the neck which comprises a float o chamber 19 in which is contained a float. 20. Desirably the upper end of the body portion I8 is formed with an inturned annular flange 2| upon which is fastened a removable head vor cover 22 by cap screws 24. Desirably a gasket 23 is interposed between the cover and flange to make a tight joint.

' Rising from the cover 22 is an annular wall 25 that provides, in its upper part, an air passage or chamber 26 and within the enclosure formed by the annular wall 26 is an annular wall 3| which joins at its top with a horizontal wall 29. Between the annular walls 25, 3| is formed an annular port 21 which connects the air passage or chamber 26 with the float chamber l9- From 5 the wall 29 extends a guide 30 in which is guided a one rriming pump, th-

avacuum tank (not shown) as is more fully set forth in my prior application above referred to.

together with the wall 36 form the supports for the walls 3|, 29 and guide 30. Desirably the cover and walls above described are cast in one piece.

The lower edge of the annular wall 3| forms a valve seat around the suction inlet port, and

surrounding the lower end of the port 21 is a valve seat 23 that is formed upon the underside of the cover 22. A valve 33 mounted upon the float rod 39 and locked thereto by a lock nut 42 is arranged to seat upon said valve seats and thereby close the entrance to the air port- 21 and the suction inlet port 32 when the float 20 is raised.

In the upper end of the air passage or chamber 26 is an air port or air inlet which opens to the outer atmosphere, and a valve 46 mounted upon the float rod 39 and locked thereto by a lock nut 41 isprovided for controlling said port. On the upper end of the annular wall is provided a valve seat 44 upon which the valve 46 seats and extending inward from the top of the annular wall 25 is an internal flange 45 which may be machined to provide a port of proper diameter. The valves 38, 46 are spaced apart upon the float rod 39 sufliciently to permit either valve to seat while the other is fully open.

As is well understood, there is more or less leakage of air through the stufling box of a centrifugal pump and usually a water seal is provided to make a leak proof joint at this place. In the present case, a suction pipe 48 may lead from the float chamber to the stufling box of the centrifugal pump whereby in case of leakage at the stufling box, any air that enters may be ex-- hausted through the suction pipe 48 instead of entering the centrifugal pump.

In the operation of the priming apparatus illustrated in Figs. 1, 2 and 3, the centrifugal pump I5 is primed by exhausting the air from the suction inlet pipe I, the fittings, the centrifugal pump and the float chamber l9, thereby causing the water to rise until 'it primes the pump and partially fills the float chamber I9. The vacuum extends through the ports 32, 21 into the air passage 26, and because of the weight of the float.

the float rod and valves, and the atmospheric pressure upon the top of the valve 46, the upward pressure of the water in the float chamber is unable to unseat the valve and seat the valve 38 until the level of the water reaches a predetermined level, as for instance, the one indicated by the reference character .1: in Fig. 2. When this level is reached. the upward pressure of the water overbalances the weight of the float and parts carried thereby, and the atmospheric pressure against the valve'46, and suddenly lifts the float 26, thereby suddenly unseating the valve 46 and seating the valve 33. The source of vacuum supply is thereupon cut oil from the float chamber, and air at atmospheric pressure is admitted to the air passage 26.

Where several centrifugal pumps are served by suction created may be suflici int to raise the pier in the float chamber of an :dle centrifugal pump high enough to completely fill the float chamber. When this condition arises, in case the valve 38 leaks, water is 2,088,981 as for instance a vacuum pump (not shown) or prevented from being drawn into the suction line because the air at atmospheric pressure in the air passage 26 will flow from the air port 21 past the lower edge of the wall 3| to the suction inlet port 32, and because of the low pressure in the float chamber, some air will escape into the float chamber forcing the water back.

By reason of the suction on the upper side of the valve 38, the float is held up after the water in the float chamber recedes far enough to ordinarily buoy up the float. Consequently, the water may recede a considerable distance before the valve38 opens, thereby enabling it to open suddenly and seat the valve 46 suddenly.

It will be seen that when the valve 38 closes and the valve 46 opens, the vacuum in the suction line 34 is not broken, and this enables the one and the same priming pump or vacuum tank to maintain its low pressure and thereby serve several centrifugal pumps.

In the form of the invention illustrated in Figs. 4 and 5, the parts, bearing reference characters similar to those used in Figs. 1, 2 and 3, designate parts corresponding to similar parts in the preferred form. In this modified form, however, instead of the annular ports 21, 32, a suction chamber 50 is formed in the space enclosed by the annular wall 25 by upright walls 49, an upper wall 49*- and a lower wall 52. The walls 49, 49 separate the suction chamberv from the air passage 26. Several suction inlet ports 5| open through the wall 52 and several air ports 54 open through the parts 53 of the bottom wall, which form the bottom wall of the air passage 26. The valve 38 seats against the lower face of the wall 52 and controls the several ports. As in the preferred form in case of a leaky valve, air under atmospheric pressure may leak'from the air ports 54 to the suction inlet ports 5|, thus preventing water from being drawn through the suction inlet ports 5| into the suction passage 33. In other respects, the operation of this form of the invention is precisely the same as that of the preferred form.

I claim as new and desire to secure by Letters Patent:

1. In priming apparatus for centrifugal pumps, the combination of a float chamber arranged for connection with the suction inlet of a centrifugal pump, said float chamber having a suc- I inlet port, a float in said float chamber. connected to and operating, when lifted, to seat said valve and when lowered to unseat the valve, and pressure operated means acting to yieldably hold the float down against upward pressure of water on the float, said pressure operated means including an air inlet passage separate from the suction inlet passage and having an inlet port opening to the atmosphere and an outlet port opening to the float chamber adjacent the suction inlet port, said suction inlet valve operating to simultaneously open said suction inlet port and air outlet port, when the float lowers, and a valve arranged to close the air inlet passage when the float is lowered.

2. In priming apparatus for centrifugal pumps, the combination of a float chamber arranged for connection with the suction inlet of a centrifug 2.1 pump, said float chamber having a suction inlet passage arranged for connection with a source of vacuum supply and being provided chamber, a valve for controlling said suction with a suction inlet port opening to the float chamber, a suction line valve for controlling said suction inlet port, a float in said float chamber connected to and operating, when lifted, to seat said valve, there being an air inlet passage separate from said suction inlet passage having an air inlet port opening to atmosphere and an air outlet port located in close proximity to the suction inlet port, and independently opening to the float chamber,said suction line valve controlling said suction inlet port and the adjacent air outlet port of the air inlet passage, and a valve for controlling said air inlet port to the air inlet passage, connected to and operated by said float.

3. In priming apparatus for centrifugal pumps, the combination of a float chamber arranged for connection with the suction side of a centrifugal pump and having a suction inlet passage arranged for connection with a source of vacuum supply, said suction inlet passage being provided with a suction inlet port opening directly to the float chamber, there being an air inlet passage separate from the suction inlet passage and having an air inlet port opening to the atmosphere and a port opening directly to the float chamber in close proximity to the suction inlet port, a valve for controlling the suction inlet port and the adjacent port of the air inlet passage, a-valve for controlling the inlet port of the air inlet passage, the two valves being connected whereby either of said valves is closed when the other is open, and a float in said float chamber for operating said valves.

4. In priming apparatus for centrifugal pumps, the combination of a float chamber arranged for connection with the suction side of a centrifugal pump, said float chamber having also a vacuum-line opening thereto through a suction inlet port, and having also an air inlet passage separate from the vacuum line and opening through an air inlet port to the outer atmosphere, said air inlet passage having also a port disposed in close proximity to the suction inlet port, and opening to the float chamber independently of the suction inlet port, a valve for simultaneously closing the suction inlet port and the adjacent port of the air inlet passage, a valve for controlling the air inlet to the air inlet passage,

- either of said valves being closed while the other is open, and a float in said float chamber connected to and operating said valves.

5. In priming apparatus for centrifugal pumps, the combination of a float chamber arranged for connection with the suction inlet of a centrifugal pump, a cover for said float chamber having a suction inlet passage therein arranged for connection with a source of vacuum supply, said suction inlet passage terminating in an annular suction inlet port opening directly to the float chamber, said cover having also an annular wall providing an air passage having an annular port surrounding the annular suction inlet port and opening to the float chamber independently of the suction inlet passage, said air passage having also an air inlet port opening to the atmosphere, a valve for controlling said air inlet and a valve for controlling both of said annular ports, either of said valves being seated while the other is unseated, and a float in said float chamber connected to and operating said valves.

6. In priming apparatus for centrifugal pumps, the combination of a float chamber arranged for connection with the suction inlet of a centrifugal V pump, a cover for said float chamber having a suction inlet passage therein arranged for connection with a source of vacuum supply, said suction inlet passage terminating in a plurality of suction inlet ports opening directly to the float chamber, the cover having also an annular wall providing an air passage separate from the suction inlet passage and terminating at one end in a plurality of air outlet ports located in close proximity to the suction inlet ports and opening only to the float chamber, and the air passage having an air inlet port, a valve for controlling said air inlet port, and a valve for controlling both the air outlet ports and suction inlet ports, either valve being seated while the other is open, and a float in said float chamber connected to and operating said valves.

7. In priming apparatus for centrifugal pumps,

the combination of a float chamber arranged for connection with the suction side of a centrifugal pump, a cover for said chamber having a suction inlet passage arranged for connection with a source of vacuum supply, and having a suction inlet port opening to the float chamber, said cover having also an air passage separate from said suction inlet passage and having an air port opening to the atmosphere and an air outlet port opening to the float chamber independently of the suction inlet port. and port controlling means for said suction inlet port and said air inlet and outlet ports including a float in said float chamber.

8. In priming apparatus for centrifugal pumps, the combination of a float chamber arranged for connection with the suction side of a centrifugal pump, and having a suction line provided with a suction inlet port opening directly to the float chamber, said suction line being arranged for connection with a source of vacuum supply, said float chamber having also anair inlet passage separated from the suction line and having an air inlet port opening to atmosphere and an outlet port opening directly to the float chamber in close proximity to the suction inlet port, whereby connection may be established between the suction line and air passage, a valve for closing and and closing said air outlet port and suction inlet port, either of said valves being closed while the other is open, and a float in said float chamber connected to and operating said valves.

9. In priming apparatus for centrifugal pumps, the combination of a float chamber arranged for connection with a suction inletof a centrifugal pump, said float chamber having a suction inlet passage arranged for connection with a source of vacuum supply and being provided with a suction inlet port opening to the float chamber, there being an air inlet passage having an air inlet port, and an air outlet port, the latter opening to the float chamber, an air inlet valve for con- I trolling the admission of air to said air passage, a

suction inlet valve for controlling said suction inlet port and air outlet port of said air inlet passage, and a float in said float chamber connected to and operating, when lifted, to unseat sa d air inlet valve and seat said suction inlet valve and thereby close the air inlet passage and the suction inlet port. whereby said suction inlet passage is closed against the admission of outside air when the-suction inlet valve is seated, whereby the suction applied to the suction inlet valve serves to hold said valve closed until overcome by the force of gravity on the float.

AUGUSTUS C. DURIDINI JR. 

